This application is a national stage application of PCT/JP2013/075745, international filing date Sep. 24, 2013, and claims priority to JP 2012-222262, filed in Japan on Oct. 4, 2012, the entire disclosures of which are hereby incorporated by reference in their entirety.
The present invention relates to an electrical junction box in which a cover is assembled to a main body provided with a circuit board, and in particular to an electrical junction box in which a cover is externally fitted to a main body and is assembled in a state in which the main body is accommodated in the cover.
Conventionally, electrical junction boxes are used in automobiles and the like in order for electrical components such as fuses, relays, and the like to be arranged space-efficiently, for example. As such an electrical junction box, an electrical junction box as disclosed in, for example, JP 2008-295263A is known that has a structure in which a cover is externally fitted to a main body provided with a circuit board such as a printed-circuit board, and the main body is accommodated in the cover.
Meanwhile, in view of the demand for downsizing in recent years, an electrical junction box as disclosed in JP 2008-295263A is configured such that a cover is externally fitted to a main body with almost no gap, and the outer surface of the main body and the inner surface of the cover face each other with a very small micro-gap.
Therefore, if water enters the cover through, for example, a gap between the open end of the cover and the main body, capillary action may occur in the micro-gap between the outer surface of the main body and the inner surface of the cover, and water may deeply enter the cover. Furthermore, there is the risk that the water that has entered the cover reaches the circuit board of the main body, resulting in a short circuit or corrosion of the circuit board.